Berry Bulletin and SWD update July 28

In this update:

-crop development

-insecticide rainfastness

-renovation

-SWD management

July 28, 2017                                                                           PDF attachedBerry Bulletin July 27

Crop development: Strawberry renovation is finishing up in southern Ontario. Summer raspberry harvest is ongoing across the province. Blueberry harvest is underway and growers are happy with the yields so far. Spotted wing Drosophila continues to be challenging for raspberry and blueberry growers to manage.

Blueberries:

Spotted wing drosophila management continues to be the most important issue for blueberry growers right now. Use the SWD registration chart now to plan your spray program. Remember to plan for rain and keep an insecticide ready in case you need to re -apply after a rain.  Control might be especially challenging this year with the frequent wet weather. Michigan state university has a lot of great resources on insecticide rainfastness and making insecticide decisions. They have developed general guidelines based on current studies, shown in this chart:

* Number of days after insecticide application that the precipitation event occurred.

Insufficient insecticide residue = Insufficient insecticide residue remains to provide significant activity on the target pest, and thus an immediate re-application is recommended.
Sufficient insecticide residue = Sufficient insecticide residue remaining to provide significant activity on the target pest, although residual activity may be reduced.

MSU Extension, Dr. John Wise, http://msue.anr.msu.edu/news/rainfast_characteristics_of_insecticides_on_fruit

Based on this information from Dr. Wise it will be important to re-apply an insecticide after a rain, or to shorten your spray schedule during wet weather.

Check out Michigan State University’ article Rainfast Characteristics of Insecticides on Fruit to learn more about using insecticides in wet weather.

Raspberries: Summer fruiting raspberry harvest is slowing down, with a week left of picking in some areas. Spotted wing drosophila is the most challenging issue for raspberry and blackberry growers right now.  Pick the fruit frequently and thoroughly, apply weekly insecticides, and cool fruit to 5C (at least) immediately after harvest to keep SWD populations under control.  Growers are also finding fruit rot from the wet weather.

Strawberries:

Renovation continues across the province.  Renovation is not just to clean up any weed problems, but to re-establish healthy plants by mid-August, when fruit bud initiation occurs. To optimize fruit bud initiation begin the renovation process as soon as possible after harvest, including weed control, row-narrowing, mowing, and fertilizer application.

Continue to scout for aphids and potato leafhoppers in new plantings and renovated fields. We have seen less leafhopper damage this week then a couple weeks ago and we are not seeing damage on new leaves.

Mark your fields for cyclamen mite damage. Agri-mek is the only product registered for cyclamen mite control now and is only registered for pre-harvest. Mark your fields now and apply agri-mek in the spring to problem areas. Beneficial mites later this summer may also help manage cyclamen mites.

After renovating and in new plantings continue to monitor for aphids. Look for aphids on the new, succulent growth after renovation. There is very little tolerance for aphids in new fields. Apply an aphicide approximately every two weeks, or sooner if you are finding more than 15 aphids on 60 leaves (1 in 4).

Warm, wet weather will spread anthracnose. Captan, Maestro and Thiram for botrytis control will also control anthracnose. Pristine and Cabrio should be tank mixed with a compatible fungicide rather than used alone for anthracnose control.

Spotted-Wing Drosophila:

We have sustained SWD catches in most of the traps we have set up across the province. In Michigan they have the ‘summer surge’ of SWD, 3-4 weeks earlier than usual. We have found over 100 flies in one of our traps and I expect the catches to jump next week. If you are not monitoring on your farm make sure you are protecting any ripe fruit- all ripening fruit is at risk. SWD management is a combination of weekly insecticides, regular, thorough picking and immediate post-harvest cooling to less that 5C or cooler. Re-apply an insecticide after a rain to maintain coverage. Renovate June-bearing strawberries as soon as possible to dry up the remaining fruit and making it less attractive to SWD.

Salt water assessments should be done regularly as an early sign of SWD problems: http://www.omafra.gov.on.ca/english/crops/facts/swd-saltwater.htm

 

Coming Events:

On Wednesday August 9th, from 7:30am-10:00am, the University of Guelph and Farms at Work is leading a farm tour showcasing Native Pollinator Habitat on Farms, held at Howe Family Farm in Aylmer. Check out the attached poster or the Eventbrite information:

https://www.eventbrite.com/e/farm-tour-native-pollinator-habitat-on-farms-tickets-35948564123